1. Field of the Invention
The present invention relates to an antenna structure, and especially to an antenna structure which suits a notebook applied to multi-frequency wireless communication.
2. Description of the Prior Art
In fast progression of the technique of wireless communication, such as wireless local area network (LAN), gradually, mobile communication systems have been built in notebooks; thereby the notebooks can still be connected with the outside for transmitting data via the mobile communication systems. The working frequencies of the technique of wireless communication have developed to multi-frequencies very early before, such as VIFI, GSM 900, GSM 1800, DCS, CDMA and WCDMA etc.
In an U.S. patent application Ser. No. 2007/0060222 titled “Combination Antenna with Multiple Feed Points”, there is a kind of combination antenna having therein a common structure for connecting a first electromagnetic radiation element and a second electromagnetic radiation element, the two electromagnetic radiation elements are provided for operating different frequency bands. The common structure includes a common antenna structure, a common mounting structure and a common grounding structure, in order that the space occupied by the first and the second electromagnetic radiation elements which are mounted separately can be saved.
The evidently not able to satisfy the requirement of mobile communication. And more, by virtue of the tendency of compacting of notebooks, the space for mounting hidden antenna becomes smaller and smaller; it is the main category of discussion of the present invention—how to design an antenna structure that can be applied to multiple frequency bands.